Isn't promoting the idea of a willing buyer and a willing seller voluntarily agreeing to exchange goods and services for money the whole foundation for most of your posts here? One of the parties happens to be a government acting on behalf of the people it represents and both parties have come to an agreement that provides mutual benefit. What precisely is the issue? The battery was sold by Tesla to the (privately owned) operator of the wind farm that tops it up, Neoen. The SA government is buying a service that provides value to it's constituents.